The wheels, pulleys, and shafts that drive the hammers whose repeated striking of heated metal (or forging) produced high-quality steel. This combination of wheels, pulleys, gears, and shafts transforms "the pushing, pulling, pressing of the hand into continuous rotation" -- a transformation that Sigfried Gideon terms the "first phase of mechanization" (47). Note, however, that wood still provides large partions of this machinery made for forging iron.